A13746. Bad Triangle
编程题
普及/提高-
知识点
题目描述
You are given an array $a_1, a_2, \dots , a_n$ , which is sorted in non-decreasing order ( $a_i \le a_{i + 1})$ .
Find three indices $i$ , $j$ , $k$ such that $1 \le i < j < k \le n$ and it is impossible to construct a non-degenerate triangle (a triangle with nonzero area) having sides equal to $a_i$ , $a_j$ and $a_k$ (for example it is possible to construct a non-degenerate triangle with sides $3$ , $4$ and $5$ but impossible with sides $3$ , $4$ and $7$ ). If it is impossible to find such triple, report it.
Find three indices $i$ , $j$ , $k$ such that $1 \le i < j < k \le n$ and it is impossible to construct a non-degenerate triangle (a triangle with nonzero area) having sides equal to $a_i$ , $a_j$ and $a_k$ (for example it is possible to construct a non-degenerate triangle with sides $3$ , $4$ and $5$ but impossible with sides $3$ , $4$ and $7$ ). If it is impossible to find such triple, report it.
输入格式
The first line contains one integer $t$ ( $1 \le t \le 1000$ ) — the number of test cases.
The first line of each test case contains one integer $n$ ( $3 \le n \le 5 \cdot 10^4$ ) — the length of the array $a$ .
The second line of each test case contains $n$ integers $a_1, a_2, \dots , a_n$ ( $1 \le a_i \le 10^9$ ; $a_{i - 1} \le a_i$ ) — the array $a$ .
It is guaranteed that the sum of $n$ over all test cases does not exceed $10^5$ .
The first line of each test case contains one integer $n$ ( $3 \le n \le 5 \cdot 10^4$ ) — the length of the array $a$ .
The second line of each test case contains $n$ integers $a_1, a_2, \dots , a_n$ ( $1 \le a_i \le 10^9$ ; $a_{i - 1} \le a_i$ ) — the array $a$ .
It is guaranteed that the sum of $n$ over all test cases does not exceed $10^5$ .
输出格式
For each test case print the answer to it in one line.
If there is a triple of indices $i$ , $j$ , $k$ ( $i < j < k$ ) such that it is impossible to construct a non-degenerate triangle having sides equal to $a_i$ , $a_j$ and $a_k$ , print that three indices in ascending order. If there are multiple answers, print any of them.
Otherwise, print -1.
If there is a triple of indices $i$ , $j$ , $k$ ( $i < j < k$ ) such that it is impossible to construct a non-degenerate triangle having sides equal to $a_i$ , $a_j$ and $a_k$ , print that three indices in ascending order. If there are multiple answers, print any of them.
Otherwise, print -1.
输入输出样例
输入 #1
3 7 4 6 11 11 15 18 20 4 10 10 10 11 3 1 1 1000000000
输出 #1
2 3 6 -1 1 2 3
说明/提示
In the first test case it is impossible with sides $6$ , $11$ and $18$ . Note, that this is not the only correct answer.
In the second test case you always can construct a non-degenerate triangle.
In the second test case you always can construct a non-degenerate triangle.